Furnace



Aug' 14, 1934 J. F. o. sTRATToN FRNACE Filed Sept. 27, 1928 atented Aug. i4, i934 .lohn F. Stratton, Pelham Manor, N. Y.

Application September 27, i928, Serial No. 308,712

(Cl. IL- 28) 4 Glaims.

The present invention relates to improvements in furnaces, is particularly' applicable to furhaces of the vertical jet combustion type, such for example as is shown in my Letters Patent No. 1,646,158.

In vertical jet combustion furnaces, the fuel is held in suspension by an upward blast of air, and the amount of air supplied in the blast is varied in accordance with the amount of fuel to be con- The non-combustible matter, being heavier than the fuel, falls against the force of the blast into an ash pit. In furnaces, wher the fuel is burned while in a suspended state, a

:small amount of finely divided solids may be entrained in the outgoing .cts of combustion.

solids are in the nature of iine cinders, and contain a small percentage of miconsumed which is usually graphitic in character. The enti ined solids baiiied out of the gases H3 of combustion, are collected in a suitable cin er chamber separate from the ash pit. The conbustible in the cinders passing over with the gases bI s only at a relatively high temperatur The primary object of the present invention resides in the ovision of novel means for automatically reting the solds collecting in the cinder chamber to the combustion chamber. By reason of this construction, the necessity of periodically manually removing the collecting so cinders, which involves :stra labor.and inconvenience, is avoided. By immediately removing the cinders, danger of fire in the cinder chamber is reduced. Also, the combustible in the cinders is not lost as would otherwise be the case, but is burned, thereby increasing the efficiency of combustion.

Another object of the invention resides in returning the cinders to the hottest part of the combustion chamber so that the combustible will be .40 consumed.

The amount of cinders passing over with the gases of combustion obviously will vary with the air pressure which in turn is varied with the amount of fuel supplied. A further object there- 4.; fore resides in the provision of a novel means of the foregoing character which will vary in capacity with the supply of air and fuel, and hence with the amount of cinders to be handled.

A more specific object resides the provision 5o of a novel suction device for removing the cinders, the device being operable by air from the air supply for the blast.

Further objects and advantages will become apparent as the description proceeds.

s In the accompanying drawing, the figure is a ortica vertical sectional view of a furnace embodying the fea res of my invention.

alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

Referring to the exemplary embodiment of the invention in the drawing, the invention is applied to a vertical jet combustion furnace of a particular construction, but it is to be understood that the invention is applicable to furnaces of a variety of constructions.

In the preferred form, the furnace comprises a combustion chamber 10 of suitable form comprising a rear wall 11, a front wall 12, and inclined rear and front bottom walls 13 and 14. These walls may be made of any suitable matew rial, such as refractory material. and 14 at their lower edges denne a narrow The walls 13 opening 1-5 defining the upper rear and front edges of a throat preferably formed by a peripheral air chamber 15, and serve to direct the coal and slag falling thereon toward the throat.

17 in the front wall 12.

Underlying the combustion chamber 10 is a Fuel, such as iinely divided coal, may be fed into the chamber 10 through a spout closed ash pit 18 which also serves as an air pressure chamber.

Ashes may be removed from the pit 18 through an opening 19 normally closed by a door 20.

The air chamber 16 opens downwardly to the ash pit 18, and is connected through a duct 21 to an air pressure chamber 22 adapted to be supplied with air under pressure from a suitable source, such as a blower (not shown). A valve or damper 23 serves as a means for controlling the supply of air to the chamber 18. suitably mounted in the ash pit 18, directly under the throat 16 is a grate mechanism 24. In

the present instance, the grate mechanism 24 defines a narrow adjustable space 25 extending longitudinally of the throat 16 and serving as a nozzle for directing a blast of air from the ash pit 18 into the combustion chamber 10.

The

grate mechanism 24 is movable transversely of the throat 16 so as to shift the region of the air blast.

Mounted in the upper part of the combustion CII chamber l0 are suitable heat absorbing tubes 26 and drums 27, and a series of baiiles 28, 29 and 3G for directing the products of combustion in a tortuous path among the tubes. The products of combustion may leave the chamber 10 through a suitable exhaust stack 3l.

Underlying the baies 28, 29 and 30 is a cinder collecting chamber 32 which is separated from the chamber 10 by the Wall 1l, and which has a rear wall 33 also constituting the rear outer wall of the furnace structure. The baiiles 28 and 29 serve to separate out any entrained solids in the gases of combustion, and the lower ends thereof are inclined rearwardly so as to direct these solids into the cinder chamber 32. The bottom of the cinder chamber 32 is closed by a suitable sliding gate 34 for giving access to the interior.

The cinders collecting in the chamber 32 are llocculent, and frequently contain a small percentage of combustible. Usually this combustible is in the form of graphitic carbon which burns only at relatively high temperatures. Means is provided for returning the cinders from the chamber 32 to the chamber 10. In the present instance, this means comprises an induction tube 35 which extends through the Walls 1l and 13. Preferably, the induction tube 35 opens to the lower part of the combustion chamber 10, which is in the hottest zone, so that any combustible in the cinders will be consumed. The noncombustible matter in the cinders then will pass with the ashes to the ash pit 18. Extending centrally a short distance into the inlet end of theinduction tube 35 is an air injection pipe 36 which is connected to a suitable source of pressure fluid, such as the air chamber 22. A suitable Valve 37 for regulating the supply of injection air is interposed in the pipe 36 outside of the furnace. It will be evident that the supply of injection air will vary with the supply of air to the ash pit 18, and hence with the amount of cinders to be handled. By reason of this construction, the cinders will be removed from the chamber 32 as fast as they collect, and will be sprayed into the hottest zone in the combustion chamber 10 Where the combustible matter Will be consumed and from where the non-combustible matter will pass to the ash pit.

It will beevident that I have provided a novel and highly advantageous furnace which is relatively simple and inexpensive in construction. By returning thecinders-to the combustion chamber, the combustible therein vwhich would otherwise be wasted is consumed, and at the same time vthe cinders are not permitted to accumulate in the cinder chamber. This prevents the possibility of the combustible in the cinders igniting in the chamber 32, and also obviates the necessity of manually cleaning the chamber at frequent intervals.

I^cla`im as my invention:

1. A furnace comprising, 'in combination, a combustion chamber having a restricted throat at its lower end, means for creating an upwardly directed it of air through said throat, -`eid ineen# inchdfng supply duct with a control valve, a source of air pressure for said means, means for introducing comminuted fuel into the upwardly directed blast, baffles for deiiecting the gases of combustion to baille out entrained solids, a chamber for receiving said baffled solids, an induction tube connecting said chambers, and an air injection pipe opening into the inlet end of said tube in said last mentioned chamber, said pipe being connected to said duct at the discharge side ci said Valve.

2. A furnace comprising, in combination, a combustion chamber having a restricted throat at its lower end, means for creating an upwardly directed blast of air through said throat, a source of air pressure for said means, means for introducing coniminuted fuel into the upwardly directed blast, baiies for deecting the gases of combustion to baille out entrained solids, a chambei` for receiving said baied solids, an induction tube connecting said chambers, and an air injection pipe opening into the inlet end of said tube in said last mentioned chamber, said pipe being connected to said source.

3. A furnace comprising, in combination, an upright combustion chamber having a rear fire wall, ineans for directing a blast of air upwardly into said chamber, an adjustable source of air under pressure for said means, means for introducing comminuted fuel into the blast, a cinder chamber disposed at the rear of said wall and out of the path of the gases of combustion, heat absorbing elements mounted in the upper end of said combustion chamber and over said wall and said cinder chamber, a plurality of baille walls disposed among said elements, certain of -l 5 said baille walls being disposed to direct the gases of combustion for a portion of their travel among said elements downwardly at a point over said cinder chamber to baille out entrained solids in the gases and to direct the solids into said cinder chamber, an induction passage opening from the lower end of said cinder chamber to the lower end of said combustion chamber to discharge the solids into the lower portion of the blast,

and an air injection line opening into the inlet i end of passage, said line being connected to said air source.

4. A furnace comprising, in combination, an upright combtion chamber, means for directing a blast of air upwardly into said chamber,

a source of air under pressure for said means, means for introducing comminuted fuel into the blast, a cinder chamber disposed out of the path of the gases of combustion, heat absorbing elements mounted in the upper end of said combustion chamber and over said cinder chamber, a plurality of baile walls disposed among said elements to baiiie out entrained solids in the gases, certain of said baffle walls being disposed to direct said solids into said cinder chamber, 

